Synchronizer coupling



P. oRR Erm. 2,414,388

SYNCHRONIZER COUPLING Filed May 24, 1943 2 Sheets-Sheet 1 Poi' Orr Carl gai/:072, and

Jan 14, 1947. P QRR ETAL 2,414,388

SYNCHRONIZER COUPLING Filed May 24, 1943 2 Sheets-Sheet 2 54 0 ff Le 53 IQ if@ l i- Patented Jan. 14, 1947 SYNCHRONIZER COUPLING Palmer Orr and Carl J. Conkle, Muncie, Ind., aS-

signors to Borg-Warner Corporation, Chicago, Ill., a corporation of Illinois Application May 24, 1943, Serial No. 488,185

13 Claims.

This invention relates to coupling devices and particularly to a control means therefor. For purposes of illustration the invention will be described with reference to a coupling of the selfshifting type, that is, one which is moved into or out of engagement in response to changes in the relative direction of torque.

In Patent No. 2,360,711 issued on October 17, 1944, to Palmer Orr, there is described a locking means for a self-shifting coupling, the locking means employing an interlock of the sliding bolt or bean type. The interlock is controlled by means of a collar which is slid axially to lock or unlock the coupling. Where weight requirements are stringent the sliding collar must necessarily be made as short axially as possible so that in certain installations its ratio of length to diameter is not great enough to prevent tilting of the collar and as a result the collar binds upon its supporting sleeve.

The principal object of this invention is to provide an improved locking device for a coupling of the type referred to which when operated does not create any binding forces. D

VAnother object of this invention ls to provide an improved control collar or ring for a locking device of the type referred to such that no bindlng forces are created regardless of the narrow-- ness of the collar.

A more specific object o1' this invention is to provide a coupling device of the self-shifting type which is axially compact and hence light in weight so as to be suitable for aircraft purposes.

A still more speciiic object is to provide a selfshifting coupling device for a two-speed aircraft reduction gear of the complex planetary type wherein either one of two elements of the planetary gear may be held against rotation to provide two reduced speeds through the gearing.

These and other objects of the invention will become apparent from the following detailed description and the accompanying drawings where- Fig. 1 is an elevation in section of a` preferred embodiment of the invention;

Fig. 2 is a fragmentary section taken on line 2 2 of Fig. 1;

Fig. 3 is a fragmentary section taken on line 3v3 of Fig. 1;

Fig. 4 is a fragmentary section of a modification of the invention; and

Fig. 5 is a plan view of the modication taken along line 5-5 of Fig. 4.

Referring now to the drawings for a detailed description of the invention the transmission is comprised of a driving shaft I0 which may be directly connectedto the engine or other source of power (not shown), a driven shaft II adapted to be connected to a propeller (not shown), a double reduction planetary gear set I2 adapted to provide two reduced drives between drive shaft I0 and driven shaft II and a coupling device I3 for effecting the changes in ratio through gear set I2. The entire mechanism is enclosed in a housing I 4 which may be mounted between the propeller and engine.

The gearing is comprised of a drive plate I5 secured to drive shaft I0 and driving a ring gear I 6. Said ring gear I6 meshes with and drives one or more planet pinion gears I'I which are the smaller of pairs of gears formed integrally as a spool and mounted to rotate about pinion shafts I8. A carrier I9 supports pinion shafts I8 and is mounted on and drives splines 20 in driven shaft II. Planet pinions II mesh with a sun gear 2I drivingly associated with a sleeve 22 rotatably mounted on driven shaft Il and having a coupling element 23 at the opposite end thereof.

The larger of the pairs of pinion gears is shown at 2l and these larger pinion gears mesh with a sun gear 25 rotatably supported on a sleeve 22, the sun gear 25 being provided with a coupling element 26 which is of enlarged diameter and of lesser axial extent than sleeve 22.

The coupling I3 is comprised of a plurality of elements including a stationary element 21 having internal helical splines 2B, the aforementioned coupling element 23 associated with sun gear 2 I, the coupling element 26 associated with sun gear 25, and a sliding sleeve 29 appropriately formed to couple either element 23 or element 26 to stationary element 21, thereby arresting the rotation o1' either sun gear 2| or sun gear 25. Coupling element 23 is comprised of short straight splines or teeth, and coupling element 26 is comprised oi.' similar short internal straight splines or' teeth.

'Ihe lowest ratio is obtained by holding sun gear 2| and the next highest ratio is obtained by holding sun gear 25. In the form illustrated i it is not contemplated that a direct drive between shafts I0 and I I will be provided.

The coupling means by which either sun gear 2I or sun gear 25 is held against rotation will now be described.

Sleeve 29 is provided with external helical splines 30 whichare adapted to engage the internal helical splines 28 on stationary element 21. Said sleeve 29 is enlarged adjacent splines 30 and is provided with external straight splines 3 3| thereat which are adapted to engage coupling element 26 on sun gear 25, the straight splines of element 26 being length as splines 3|. Substantially mid-way between splines 39 and 3| and located within sleeve 29 are short straight internal splines. 32 which are adapted to engage coupling element 23 on sun gear sleeve 22. Nested within the enlarged portion of sleeve 29 are additional straight splines 33 on sleeve 22 associated with sun gear 2| Referring now to Fig. 2, it will be observed -that every third tooth of the splines 26 is of normal size and the two intermediate teeth are of reduced height. Similarly, every third tooth of splines 33 ls of normal height and the intermediate teeth are of reduced height. The purpose of this construction is to accommodate a pair of pawls 34 and 35, pawl 34 cooperating with splines 26 and pawl 35 cooperating with splines 33. A spring 36 normally biases pawl 34 into engagement with splines 26 and a similar spring 31 normally biases pawl 35 into engagement with splines 33. Pawl 34 is mounted on a pin 3 extending axially from the end of sleeve 29 and Y in like manner pawl 35 is mounted on a pin 39 which is also mounted in the end of sleeve 29. Since splines 29 and 39 which serve to couple sleeve 29 to iixed element 21 'are helical, sleeve 29 will tend to move axially in response to changes in direction of torque impressed` upon the sleeve 29. It will be observed from the arrangement of gearing shown in Fig. 1 that when sun gears 2| and 25 rotate they rotate in the same direction but sun gear 25 always rotates faster than sun gear 2| except in the brief instant during which a change in direction in rotation takes place. Sleeve 29, however, is relatively stationary since it swings through only a fraction of a circle in either direction. From these observations it will be apparent that when both sun gears rotate clockwise as viewed in Fig. 2, pawl 34 will be the driver and when the direction of rotation is counterclockwise as viewed in Fig. 2, pawl 35 will be the driver. When pawl 34 is the driver, sleeve 29 is advanced toward the right (Fig. 1) to engage external splines 3| with internal splines 26, thereby arresting the rotation of sun gear 25. In order that pawl 34 be the driver, however, it is necessary thatthe speed of drive shaft |9 drop below the speed of driven shaft that is, it is necessary to close the throttle of the engine or in some other suitable fashion to apply a brake to drive shaft |9 while permitting driven shaft to rotate at substantially the same speed. Since holding sun gear 25 provides the higher of the two ratios, that is, provides a lesser speed difference between the speeds of shafts |9 and an upshift may be secured by the simple expedient of slowing down drive shaft |9. l

To secure a downshift while keeping the speed of the driven shaft substantially constant requires that the drive shaft I9 be accelerated. During such acceleration of the drive shaft I9 and, in fact, for as long as drive shaft |9 tends to drive driven shaft sun gear 25 will rotate faster than sun gear 2| in a counterclockwise direction (Fig. 2) thereby causing -pawl 35 to become the driver and tomove sleeve 29 to the left as viewed in Fig. 1 so as to engage internal splines 32 on sleeve 29 with external splines 23 on sun gear sleeve 22. The pawls 34 and 35 are so related with respect to teeth 3| and 32 respectively, that said teeth are perfectly aligned with their mating splines when the pawls drive sleeve of about the same axialI 29 in a direction to engage the teeth on the sleeve with the said splines.

The relative axial disposition of internal splines 32 and pawl 35 is such that when internal splines 32 of sleeve 29 are completely out of engagement with the external splines 23 on sleeve 22 as, for example, when sun gear 25 is stationary, pawl 35 is likewise completely out of engagement with splines 33. This is also true of pawl 34 when sun gear 2| is stationary and sun gear 25 is rotated. Both pawls completely leave' their associated splines at the extreme ends of their axial travels. This avoids unnecessary noise and wear; the pawls being used merely to bridge the axial gap between splines 33 and 26 when splines 32 and 3| lare completely disengaged from their associated sun gear splines.

Since sleeve 29 moves axially in response to torque variations, the transmission would continually shift between its two ratios unless some locking means were provided for the sleeve. This locking means is comprised of a bolt 49 shown in the form of a ball for purposes of illustration, the bolt being retained in a slot 4| instationary element 21. Sleeve 29 is provided with spaced depressions or grooves 42 and 43 into which bolt 49 is adapted to move. The splines between the depressions 42 and 43 are relieved a-s shown at 44 to facilitate movement of the bolt between depressions. Referring now to Figs. 1 and 3, bolt 49 is retained in a ydepression by means of a ring 45 the eiective peripheral length of which need not exceed sixl or seven diameters of bolt 49. Ring 45 is provided with a depression 46 into which bolt 49 may be cammed when sleeve 29 is moved from one of its extreme positions to the other. As long as depression 46 is not aligned with bolt 49, said bolt is locked in place, as is likewise sleeve 29, thereby rendering the transmission independent of changes in relative direction of torque transmission as between shafts |9 and ll. To permit a shift, however, ring 45 is oscillated so as to align depression 46 with bolt 49 and sleeve 29 then is freed to move as necessary, ring 45 being shifted so as to misalign depression 46 with bolt 49 after the shift of sleeve 29 has been completed. 1-

To facilitate control of ring 45 two ears 41 and 48 are provided on ring 45 defining a slot 49 in which may be dropped the end 59 of a lever 5|. Said lever 5| is mounted on a rock shaft 52 retained in a bearing 53 formed in housing I4. The outer end of shaft 52 is secured to a lever 54 which may be controlled in any suitable manner by the operator.

Since bolt 49 may be locked or unlocked merely little tendency of the ring to bind on element 21 and hence a more dependable control for bolt 49 15 provided by this invention.

In the modification shown in Figs. 4 and 5, the ring 45 has been dispensed with entirely and rock shaft 52 has been moved toward the left of the housing shown in Fig. 1 and lever 5| has been shortened so'as to approximate a circular plate 55. Said plate has a. depression or groove 56 milled across the bottom face thereof which performs the same functions as depression 46 in ring 45. When shaft 52 is rocked, plate 55 rotates with it and groove 56 is moved from a position locking bolt 49 against sleeve 29, through a through which the effective portion of groove 56 7 of movement of the shiftable member to lock the shiftable memberin place.

*12. A vcoupling as described in'claim '7, the interttin'g connection with the third member being substantially spiraled such that the shiftable f one of which is rotatable relative to the other,

said device including a coupling element having a spiraled splined connection with one of said members, and thereby being shiftable in response to changes in relative direction of torque transmission between said two members, locking means movable into the pathr of movement of the shiftable element to lock said element against movement, and control means for the locking means, said control means comprising an abutment oscillatable over the locking means such that in one position the locking means is held in the path of movement of the shiftable element and in another position the locking means is permitted to move out of the said path of movement, said abutment comprising a ring coaxially disposed with respect to the members to be coupled and a lever for oscillating the ring.

PALMER ORB.

CARL J. CONKLE. 

